hello,guys , a buddy of mine has a major problem here with a 1996 2WD F-150 5 Speed . SO far he replaced

-front calipers
-all brakes lines ( front and back)
-Flex lines ( going to the calipers)
-Master cylinder
-Power brake booster

So our problem is we Can not get any brake pedel at all . we Bled the system about 10 times and yet nothing . Everytime we bleed the system it bleeds normally and No air is coming from the lines or master cylinder just streight Fluid , What happens is when you pump the brake Pedel numurous times ( lets say for bleeding ) it will get some What Hard ( about 1/2 -3/4 pedel Hard ) then Once you let off the pedel and leave it for about 1 minuite and press it again it will Then go directly to the floor and we can keep doing that all day and same result . here is the bleeding cycle we use

Master cylinder ( bleed from the 2 lines going in )
back Pass side
Back driver side
Front pass
front driver
then the pressure differential valve that is on the Frame

everything bleeds fine but No matter what we do if we pump it it will get some what hard ( like Normal ) but after you leave it sit for about a min then press the pedel it will go directly to the floor like nothing . it seems there is still lots of air in the system , but we checked all over for leaks and everything looks great . also since we replaced everything the truck hassent been started at all. What can we do.

 

If you haven't "bench bleed" the master cylinder do that first, then connect the lines and bleed them.

Let the motor idle as you bleed "pumping the pedal" style, be sure its getting a full stroke each time.

 

Yes you have got to be sure that the master cylinder is properly bled first. Then, when bleeding each wheel, hold the pedal down until the bleed screw is tight then let pedal up, open bleed screw and repeat. There should be a Rear Anti-lock Brake System valve block on the left side frame rail, this needs to be bled after the two rear brakes but before the front. Also make sure the rear brake shoes are properly adjusted up.
Good luck.